Someone was after information on K-Class submarines that the UK made near the end of WW1. I picked up a book which had a whole chapter on them, it makes for sacry reading (Because of the K Class 13 was never used as a sub designation again!

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The M class was based on the the design of the K class, which didn't help them in any way!
Someone asked me for info, but I can't find the old post. So, if your still looking drop me a PM or just reply